Managing mealybugs as vectors of GLRaV
and New Virus Problems for Vineyard
Managers
Sustainable Ag Expo
Kent Daane, Christina Wistrom, Kai Blaisdel, John Hutchins,
Brian Hogg, Janice Chen, Brady Chavez, Ashfaq Sial,
Glenn Yokota, Monica Cooper, Rodrigo Almeida
Special thanks to Marc Fuchs & Deborah Golino for GRBaV
Vectors of Viral Pathogens in Vineyards Grape Red Blotch Virus Vectors Control options
Grapevine Leafroll Associated Viruses Vectors Control options
Dr. Keith Perry Cornell University
Ithaca, NY
Dr. Mysore Sudarshana USDA-ARS Davis, CA
Dr. Marc Fuchs Cornell University
Ithaca, NY
UC Davis, Napa, Mendocino Seminars Dr. Marc Fuchs ([email protected]) Red blotch: Challenges and opportunities http://fpms.ucdavis.edu/ (Foundation Plant Service – UC Davis)
Fanleaf First description 1841
Graft transmission 1962
Virus recognition 1960
Vector transmission 1958
Diagnostic assays 1960
Koch’s postulates 1962
Red Blotch: Challenges and opportunities
Leafroll 1905
1935
1979
1984
1984
n/a
Red Blotch 2008
2012
2012
2013
2012
2013
Vectors of Viral Pathogens in Vineyards 1. GLRaV Factors that Impact Control a) mealybug and leafroll species b) facts about mealybug-leafroll epidemiology 2. GLRaV Control Programs a) mealybug insecticides: which are best b) vineyard/areawide resistance management 3. What do We Know about Red Blotch? a) biology and ecology b) spread (grafts and vectors)
Vectors of Viral Pathogens in Vineyards 1. GLRaV Factors that Impact Control a) mealybug and leafroll species b) facts about mealybug-leafroll epidemiology 2. GLRaV Control Programs a) mealybug insecticides: which are best b) vineyard/areawide resistance management 3. What do We Know about Red Blotch a) biology and ecology b) spread (grafts and vectors)
photo courtesy of Deborah Golino
Grape vine leafroll associate virus: We will discuss insecticides for control of the ‘epidemic’
leafroll scenario that growers were initially worried about.
photo courtesy of Deborah Golino
…and also the mysterious arrivals of GLD
•>700 plant viruses •ca. 70% have insect, mite, nematode or fungal vectors
Martelli 2000. Proc. ASEV
aphids
whiteflies
soft scales
GLRaV Insect Vectors
GLRaV Insect Vectors •>700 plant viruses •ca. 70% have insect, mite, nematode or fungal vectors •most GLRaVs are closterovirids, which are vectored by whiteflies, mealybugs, aphids and soft scale
Martelli 2000. Proc. ASEV
aphids
whiteflies
soft scales
GLRaV-3 Mealybug Vectors in California
Vine mealybug Citrus mealybug
Obscure mealybug Grape mealybug Longtailed mealybug
The native grape mealybug (Pseudococcus maritimus) is the prevalent species and the likely historical vector of GLRaV in
most of California
The invasive vine mealybug (Planococcus ficus) is now
present, but does not explain past GLRaV movement
Gill’s mealybug
Rosciglione and Gugerli, 1987, Engelbrecht and Kasdorf 1990, Golino et al. 2002, Charles et al. 2006, Tsai et al. 2011
Obscure mealybug
Key Transmission Facts – Acquisition •Crawlers acquired virus w/in 1 hr •Peak at 24 hr
Tsai, Almeida et al. Phytopath. (2008)
Key Transmission Facts – Inoculation •Crawlers inoculated virus w/in 1 hr •Peak at 24 hr
Tsai, Almeida et al. Phytopath. (2008)
Numbers and seasonal presence of dispersal stages (crawlers) may be most important
Jan Jul Nov Sept Aug Dec Feb Apr Mar Jun Oct May Jan
Obscure mealybug
Vine mealybug
Lecanium scale
Grape mealybug
Cottony vine scale
4-6 gen/yr in Central Coast
3 gen/yr
Which leafroll species do you have?
Sharma et al. PLos One. 2011
What may be key is that viruses do change Eight GLRaV-3 strains found (to date) in Napa
vineyards, with multiple stains in some vineyards.
GLRaV-3aGLRaV-3bGLRaV-3cGLRaV-3dGLRaV-3eGLRaV-3fGLRaV-3abGLRaV-3acGLRaV-3adGLRaV-3bcGLRaV-3bdGLRaV-3cdGLRaV-3abc
a
b c
d e
f
Sharma et al. PLos One. 2011
Vectors of Viral Pathogens in Vineyards 1. GLRaV Factors that Impact Control a) mealybug and leafroll species b) facts about mealybug-leafroll epidemiology 2. GLRaV Control Programs a) mealybug insecticides: which are best b) vineyard/areawide resistance management 3. What do We Know about Red Blotch a) biology and ecology b) spread (grafts and vectors)
2 3 0 1
0
20
40
60
80
100
“3” Severe damage / lost cluster “2” Partial damage “1” Minor damage “0” No damage
Rating system for fruit damage
Dam
age
(% c
ateg
ory)
Back in the day… chlorinated hydrocarbons (DDT), OPs (parathion) and carbamates (Lannate) were used for grape mealybug control In the 1990s, Chemical Industry and UC sought alternatives to in-season OPs and Carbamates
Spray Volume: 100 GPA; Air-blast Sprayer; label rate. Details in Daane et al. 2006. Calif. Agricul. 60(1): 31-38.
Vine mealybug (P. ficus) was the target pest; Del Rey, CA.
Admire Applaud
Lorsban (as a delayed-
dormant
Control 0
40
60
80
100
20
b a b b
Frui
t dam
age
(% c
ateg
ory)
Admire (Imidacloprid)
Applaud (buprofezin)
Lorsban (chlorpyrifos)
Control
b
a
b b
0
10
20
30
40
0
5
10
15
20
25
30
Buprofezin (Applaud)
Acetamiprid (Assail)
Clothianidin (Belay /Clutch)
Spirotetramet (Movento)
Control
b b
c
a a
Spray Volume: 100 GPA; Air-blast Sprayer; label rate (Applaud 12 oz per ac) Clutch & Movento on 21 June 2011, Applaud & Assail on 7 July 2011
Planococcus ficus, Lodi-Woodbridge wine grapes, Lodi, CA
Since the 1990s, there are many novel materials. Here, I focus on Movento, Admire, Applaud, Clutch, Assail, & Lorsban
Buprofezin Acetamiprid Clothianidin
Spirotetramet Control 0
20
40
60
80
100
Frui
t dam
age
(% c
ateg
ory)
Cabernet Sauvignon
(2008)
Grape MB & Red Blotch (?)
Grape MB & GLRaV-3
In a newly planted block, two treatments: insecticides vs control
Can we simply kill all mealybugs for GLRaV control?
Highw
ay 29
GLRaV weak source block
GLR
aV m
oder
ate
sour
ce b
lock
GLRaV strong source block
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Insecticide
Control 11911711511311110910710510310199979593918987858381797775737169676563615957555351494745434139373533312927252321191715131197531
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row “1” missing
Two annual applications of a combination
of either Applaud,
Admire, Clutch or Movento
2009
2010
2011
2011
2011
2011
2011
2011 GLRaV3b
GLRaV3a GLRaV3c GLRaV3d
2012
2012
Where did the GLRaV-infected vines appear?
Insecticides No insecticides
0
5
10
15
20
25
30
Buprofezin (Applaud)
Acetamiprid (Assail)
Clothianidin (Clutch)
Spirotetramet (Movento)
Control
b b
c
a a
Spray Volume: 100 GPA; Air-blast Sprayer; label rate (Applaud 12 oz per ac) Clutch & Movento on 21 June 2011, Applaud & Assail on 7 July 2011
Planococcus ficus, Lodi-Woodbridge wine grapes, Lodi, CA
Insect growth regulator Applaud (Buprofezin)
Neonicotenoids Admire (Imidacloprid) Clutch (Clothianidin) Assail (Acetamiprid)
OPs and Carbamates Lorsban (Chlorpyrifos)* Lannate (Methomyl)* Dimethoate* *Listing here materials still effective and still registered
Biosynthesis inhibitor Movento (Spirotetramet)
Novel materials Insect must feed Slower kill (1-7 days) Relatively low residual
In ‘clean’ block remove the
infected vines
Treat source blocks to lower
populations
Treat new blocks to kill dispersing
crawlers
What about Areawide Control of Mealybugs / GLRaV?
If source blocks can eventually be pulled…
Continue to remove infected
vines and treat for dispersing crawlers
What about Areawide Control of Mealybugs / GLRaV?
1) Pheromone traps 2) Areawide mating disruption 3) Insecticides as needed
Attempted Areawide Vine Mealybug Control
♂ VMB per trap: 0 1-10 11-20
21-50 51-100 >100
2011 2012
Can Mating Disruption be Used as a Preventative? Comparison of ‘hot spots’ using pheromone traps
Results for 1 of 3 sites, shows that further spread can be prevented, and that farmers must work together.
Comparison of traps in hotspots between years
Tota
l num
ber P
l. fic
us m
ales
/ tra
p
2011 2012
0
50
100
150
200
250
300
Numbers of Pl. ficus in traps with total >20 VMB in either year generally decreased between 2011 and 2012, except in two cases.
When proper treatments are not applied the population will increase and spread.
Increase Decrease No change
Insecticides for ‘high density’ vine mealybugs Mating disruption to prevent spread Rogue vines (up to 20% infestation)
Vectors of Viral Pathogens in Vineyards 1. GLRaV Factors that Impact Control a) mealybug and leafroll species b) facts about mealybug-leafroll epidemiology 2. GLRaV Control Programs a) mealybug insecticides: which are best b) vineyard/areawide resistance management 3. What do We Know about Red Blotch a) biology and ecology b) spread (grafts and vectors)
Discovery of Leafroll Disease • Description of “rougeau” in France (Ravaz and Roos,
1905; Pacottet, 1906) and ”rossore” in Italy (Arcangeli, 1907)
• Graft-transmission (Scheu, 1935)
• Association of a virus (Namba et al., 1979)
• Serologically distinct viruses associated with the disease (Gugerli et al., 1984; Rosciglione and Gugerli, 1986)
• Mealybug transmission (Rosciglione and Gugerli, 1987)
• Koch’s postulates have yet to be fulfilled
Maree et al. Frontiers in Microbiology 4:82 (2013)
Discovery of Red Blotch Disease
• First description in Napa Valley (Calvi, 2008)
• A new DNA virus sequence (Krenz et al., 2012)
• Diagnostic tools made available (Krenz et al., 2012; Al Rwahnih et al., 2012)
• High correlation between virus presence and diseased vines (Al Rwahnih et al. 2013)
• Graft transmissibility (Al Rwahnih et al. 2013)
• Koch’s postulates are being tested by Dr. Fuchs
Pinot noir
Cabernet franc
Chardonnay
Grape Red Blotch (that looks like GLRaV)
PCR Diagnosis – TEST, DON’T GUESS! •Any tissue
(Leaf, petiole, dormant canes, clusters) •Any time
Fall and winter
slower berry ripening w/ GRBaV lower Brix w/ GRBaV
Distribution of GRBaV-infected vines
Genome Structure of a Circular Viral DNA
Protein Function V1 coat protein V2 unknown (movement?) V3 unknown (movement?) C1 replicase C2 replicase C3 likely not expressed
GRBaV 3206 bp
V2
V1
V3
C1
C2
TAATATT AC
C3
Grapevine red blotch-associated virus (GRBaV)
GRBaV replicase groups most closely with viruses of the genus Mastrevirus
Grapevine red blotch-associated virus
Treehopper
Leafhopper
Leafhopper
Whitefly
GRBaV coat protein groups separately from the other four genera of the family Geminiviridae
Grapevine red blotch-associated virus
Dissemination • Propagation
• Grafting
• Anecdotal evidence suggests spread in certain
vineyards
• Virginia creeper leafhopper can transmit GRBaV from grapevine to grapevine in the greenhouse (Poojari et al., 2013)
Koch’s Postulates for GRBaV – Dr. Fuch’s Laboratory • Pathogen must be present in all cases of the disease • Pathogen isolated from diseased host & grown in pure culture • Pathogen must cause disease when inoculated into a healthy host • Pathogen must be re-isolated from the new host and shown to be
the same as the originally inoculated pathogen
http://fpms.ucdavis.edu/ (Foundation Plant Service – UC Davis)
• Red blotch is a recently recognized disease, associated/caused by a newly discovered DNA virus (two distinct genetic variants of GRBaV)
• Delayed fruit ripening, reduced Brix
• Microshoot tip culture is not efficient at curing
• GRBaV is graft-transmissible, and some GRBaV spread in vineyards over time has been recorded
• Virginia creeper leafhopper may transmit GRBaV
• Symptoms can be misleading. Test, don’t guess!
Red Blotch: What Do We Know?
1. Etiology • Reproduce symptoms
Grafting? Leafhopper transmission?
• Visualization of virus particles
2. Detection • Optimize PCR • Serological assays • Seasonal distribution in infected vines • Latency period for symptom development
Red Blotch: What Don’t We Know?
3. Ecology • Vector(s) • Transmission from grapevine to grapevine in
vineyards
Red Blotch: What Don’t We Know?
3. Ecology • Vector(s) • Transmission from grapevine to grapevine in
vineyards
Red Blotch: What Don’t We Know?
Currently mapping blocks with GRBaV and GLRaV and comparing infection patterns with insect presence and cultural practices
Healthy vines
GRBaV
3. Ecology • Vector(s) • Transmission from grapevine to grapevine in
vineyards
4. Interaction of GRBaV and other viruses • Synergistic/antagonistic/commensalistic
relationships?
5. Improve elimination therapy methodologies • Meristem culture • Embryogenic culture
Red Blotch: What Don’t We Know?
6. Effect of GRBaV on vine health • Comparative performance evaluation • Tolerant cultivars • Tolerant rootstocks
7. Management • Clean stocks
Red Blotch: What Don’t We Know?
Thank you, Questions? ‘GLRaV & MB’ Collaboration & Help:
Walter Bentley, Jocelyn Millar, Lucia Varela, Rhonda Smith, David Haviland and numerous cooperating vineyards and vineyard managers
Support:
Associate, ‘FAR’ & Sterling Insectaries, Foundation Plant Services, Suterra Inc.
Laboratory direction & help :
Tina Wistrom, John Hutchins, Monica Cooper, Glenn Yokota, Vaughn Walton, Korey Kasir, Kevin Welzel, Karen Sime, Marcos Botton, Betsy Boyd, and Raksha Malakar-Kuenen